The present invention relates to apparatus for manipulating sheets which consist of paper, cardboard, metallic foil, synthetic plastic material or a combination of such substances, and more particularly to improvements in apparatus for changing the orientation of stacked sheets between successive processing stations or the like.
It is often necessary to change the orientation of (especially to rotate) stacked paper sheets or the like between a first processing station at which the stacks must be held in a first position and a next-following processing station at which proper treatment of stacks necessitates that the stacks be held in an entirely different position. For example, a stack of sheets is gathered and trimmed at a preceding station, and one edge face of each sheet in a freshly assembled stack must be coated with a suitable adhesive at the next station. The nature of the adhesive applying device at the next station may be such that the entire stack must be rotated through a certain angle about a vertical axis in order to move the selected edge faces of sheets in a stack to an optimum position for the application of adhesive. Elongated rectangular sheets can be assembled into stacks at a first station from which the freshly assembled stacks are removed by advancing the sheets lengthwise so that one shorter edge is located at the leading end of each sheet in the freshly assembled stack. On the other hand, the paster which applies adhesive to one of the shorter edge faces of each stack is adjacent to the path of lengthwise movement of the stack so that it is necessary to turn each stack through 90 degrees prior to arrival at the adhesive-applying station.